Developmental trajectories, heterogeneity, and influencing factors of loneliness among Chinese higher vocational college students: a longitudinal study

Higher vocational college students face multiple stressors such as skills competition and academic stigma, which may lead to distinct developmental patterns of loneliness. However, existing evidence is largely cross-sectional and lacks direct longitudinal examination of such dynamic processes. This study aimed to investigate the overall trend, heterogeneous trajectories, and predictors of loneliness among vocational college students, with a particular focus on the roles of self-identity, self-esteem, and family climate. A longitudinal design with three measurement waves over two years (6-month intervals) was conducted among 508 vocational college students. Latent growth modeling (LGM) was used to examine the overall developmental trend of loneliness. Latent class growth analysis (LCGA) was applied to identify heterogeneous trajectories. The R3STEP robust three-step method was employed to test the predictive effects of baseline self-identity, self-esteem, gender, and family climate on trajectory membership. Parallel process growth models examined the dynamic associations between change rates of self-identity, self-esteem, and loneliness. (1) No significant linear change in loneliness was observed overall, but significant inter-individual differences in initial levels and change rates existed. (2) LCGA identified three trajectories: high-loneliness stable (28.9%), moderate-loneliness increasing (46.5%), and low-loneliness decreasing (24.6%), with good classification quality. (3) R3STEP analysis showed that higher levels of self-identity and self-esteem significantly reduced the probability of belonging to high-risk trajectories, whereas gender showed no significant predictive effect. Regarding family climate, the variable exhibited near-complete separation from trajectory membership: the vast majority of students reporting a poor family climate were classified into high-risk trajectories, with very few appearing in the low-decreasing group. Firth‘s penalized likelihood regression confirmed a consistently positive directional effect, indicating that poor family climate is a substantial risk factor for persistent high loneliness. (4) Parallel process models revealed significant negative associations between changes in self-identity and loneliness, and between changes in self-esteem and loneliness. The development of loneliness among vocational college students is heterogeneous. Self-identity and self-esteem are important protective factors, while poor family climate is a risk factor for persistent high loneliness. Our findings further demonstrate that changes in psychological resources are closely associated with dynamic changes in loneliness. Targeted interventions should focus on the critical early window following college entry, and aim to enhance students’ self-identity and self-esteem.